Reacción #6294

Ecuación de reacción

sodium chloride

4-(N-2-acetoxyethyl-N-ethylamino)benzaldehyde

1,3-dioxolan-2-ylmethyltributylphosphonium bromide

Potassium t-butoxide

→

cinnamaldehyde

4-(N-2-hydroxyethyl-N-ethylamino)cinnamaldehyde

Disolventes

dimethylformamide

dimethylformamide

HCl

water

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaheating
2. 2
   TemperaturaAfter cooling to room temperature
3. 3
   SecadoThe combined organics are dried over 4A sieves
4. 4
   Filtraciónfiltered through cotton
5. 5
   Otroevaporated
6. 6
   OtroThe crude reaction product
7. 7
   ExtracciónAfter neutralization with saturated sodium bicarbonate, the aqueous mixture is extracted with three portions of ether
8. 8
   Secadothe combined organics are dried over 4A sieves
9. 9
   Filtraciónfiltered through cotton
10. 10
    Otroevaporated

Procedimiento

To a solution of 235.3 g (1 mole) of 4-(N-2-acetoxyethyl-N-ethylamino)benzaldehyde in dimethylformamide is added 738.7 g (2.0 moles) of 1,3-dioxolan-2-ylmethyltributylphosphonium bromide in dimethylformamide, and the mixture is heated at 90° C. Potassium t-butoxide (224.4 g, 2.0 moles) is added, and heating is continued at 90° C. for 16 hours. After cooling to room temperature, the solution is poured into a seven-fold excess of water, the aqueous mixture is saturated with sodium chloride, The combined organics are dried over 4A sieves, filtered through cotton, and evaporated. The crude reaction product is dissolved in 3M HCl, and the reaction is stirred at room temperature for 16 hours. After neutralization with saturated sodium bicarbonate, the aqueous mixture is extracted with three portions of ether, and the combined organics are dried over 4A sieves, filtered through cotton, and evaporated to yield the cinnamaldehyde as an oil. The product is purified by flash chromatography (silica gel, 1:1 hexane:ethyl acetate).

Fuente